To Lawson Tait   20 July [1875]1

Down, | Beckenham, Kent. | Railway Station | Orpington. S.E.R.

July 20th

My dear Sir

I despatched of course your article.—2 I read it rather hurriedly to catch morning post. I will read it deliberately when published.— If you have succeeded in separating the ferment the fact is manifestly most important.3 Did you try whether the fluid from pitchers with no animal matter could digest? This, I think, ought to have been done to prove that there was ferment in the fluid.4 Glad to hear about the passage for guiding insects, as I speculated & told Hooker I guessed that this was the case.—5

Yours sincerely | Ch. Darwin

ALS (photocopy)

1
The year is established by the reference to Tait’s note in Nature (see n. 2, below).
2
Tait had sent a note on insectivorous plants with his letter to CD of 19 July [1875]; it appeared in Nature, 29 July 1875, pp. 251–2.
3
Tait claimed to have separated a substance closely resembling pepsin from the secretions of Drosera dichotoma (now D. binata, forked-leaf sundew) and various tropical pitcher-plants (Nepenthes). See letter from Lawson Tait, 15 July [1875] and n. 5.
4
CD had given this advice in his letter to Lawson Tait, 17 [July 1875].
5
Tait described a channel on the back of the pitcher in Nepenthes that served as a guide for insects to enter the fluid-filled reservoir (Nature, 29 July 1875, p. 252). Joseph Dalton Hooker was working on the digestive properties of Nepenthes (Correspondence vol. 21).

Manuscript Alterations and Comments

1.1 morning] interl
1.4 have been] ‘have’ interl; ‘been’ altered from ‘be’
1.5 prove] after del ‘shew’

Please cite as “DCP-LETT-10080,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-10080